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<head>
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    <title>Document</title>
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<body>
    <!-- 
        实现两列布局
        左边固定宽度 100px 红色北京
        右侧自适应宽度 黑色北京
     -->

<div style="width: 100%;height: 100px;display: flex;">
    <div class="left" style="background-color: red;width: 100px;height: 100px;"></div>
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